1. Field of the Invention
The present invention relates to a production apparatus for a wiring harness arranged in a mobile unit such as a motor vehicle.
2. Related Art
A motor vehicle has a wiring harness for supplying a power to electrical appliances such as various lamps and motors from a battery. A conventional wiring harness includes a plurality of electrical cables, a plurality of terminals each fitted to an end of each electrical cable, connector housings accommodating the terminals, etc.
An ordinary or high grade car has an increasing number of on-vehicle electronics components, which requires hundreds to thousands of electrical cables. Thus, a wiring harness for such a car tends to have an increasing number of electrical cables.
For assembling the wiring harness, a plurality of sub-wiring harnesses which has a plurality of electrical cables and connectors, are assembled. Thereafter, these sub-harnesses are combined with one another to complete the wiring harness. Thus, the wiring harness production line has a plurality of sub-harness assembling lines and a wiring harness assembling line.
For assembling the sub-harness, each sub-harness assembling line press-fits or crimps a terminal to each end of each one of plural electrical cables. If required, the electrical cables are directly connected to one another by crimping or the like. Thereafter, these terminals are received in terminal accommodation chambers of connector housings to assemble the sub-harness.
The wiring harness assembling line combines the sub-harnesses with one another to obtain the wiring harness. The wiring harness assembling line has used, for example, a plurality of wiring boards. The wiring board travels on a circulation course on a floor of a factory and has clips for bundling the electrical cables. On the wiring board, the electrical cables are crimped at predetermined points to arrange the electrical cables and the sub-harnesses to obtain the wiring harness.
However, the conventional wiring harness production line has the plurality of sub-harness production lines which are independent of each other. Thus, each sub-harness production line has a specified time for producing a single sub-harness, and the specified time is different from that of another sub-harness production line.
Some electrical cables of the sub-harnesses are directly connected to each other. Such electrical cables of the sub-harnesses should be once transferred from an automatic assembling line having a known crimping machine to a known joint crimping machine or a conventional resistance welding machine.
The direct connection of the electrical cables varies a time requested for assembling the sub-wiring harnesses. Thus, the sub-harness assembling lines vary from each other in their assembling times.
The wiring harness assembling line needs to stock an amount of the sub-harness. The wiring harness assembling line uses the stocked sub-harnesses to complete the wiring harness, so that the wiring harness assembling line receives an appropriate number of the sub-harnesses in consideration of the work progress.
Therefore, the conventional wiring harness production apparatus requires a space for stocking the sub-harnesses in the wiring harness assembling line. This tends to increase an installation space of the apparatus in a factory. Furthermore, the stock of the sub-harnesses in the wiring harness assembling line may be undesirable for the reliability of the sub-harnesses. The decreased reliability of the sub-harnesses has an adverse effect on the wiring harness.